1. Field of the Invention
The invention presented here is in the field of systems for displaying realistic, virtual three-dimensional images in real time.
2. Description of the Related Art
Many devices for the display of realistic and virtual-reality images are known from the prior art. In particular, systems for flight simulation contain a database of geographical information, corresponding to real or invented landscapes, and the software renders an image corresponding to the user""s position at a given instant relative to the base elements.
The European patent EP 0817 133 A (issued to SUN MICROSYSTEMS INC.) describes a system that allows the display of virtual objects in the real environment. The system contains a screen, a camera, a system for positioning by telemetry and a system for calculating the virtual image in two dimensions relative to the real environment. The image calculated in this way is then superimposed on the image taken by the camera.
This system has certain limits notably with regard to the system of telemetry, in fact, this type of locating system does not allow certain applications in large spaces with precise positioning.
On the other hand, this display system is completely isolated and does not allow any interactivity with other similar devices. In fact, the storing of the position of the object is contained in the internal memory of the system. This aspect limits the realism of the system since only one user can display the object, move it, and observe it in another position. Each user thus navigates among his own virtual objects and totally ignores those of the others. This system thus does not allow the creation and the display of a virtual environment shared among many users superimposed on the real environment in a manner common to all users.
The U.S. Pat. No. 5,556,073 (issued to Margolin) describes a system to help in piloting. The system consists of a OPS that makes it possible to determine the position of the airplane. A database contains a virtual representation of the environment of the airplane. As a function of the position of the airplane, it is thus possible to display the virtual environment without being concerned with the real environment. The display of the environment can be done using a display helmet. This type of system does not make it possible to superimpose a virtual environment on the real environment, but just allows the substitution of the real environment with a virtual environment that takes on the characteristics of the real environment.
The U.S. Pat. No. 4,970,666 (issued to Welsh et al.) describes a system for representing virtual images in a real environment. The images of the real environment are numbered and then the representation of the virtual image is positioned relative to the numbered image. The two images are then superimposed. This type of system only makes it possible to process fixed images but not to simulate a virtual object in recalculating its image as the user is moving and in superimposing this image on the real environment. On the other hand, this system makes it possible to add lighting effects to the image, for example. Once again, this operation is very easy in the case of fixed images, but becomes very complex in the case of a moving user where the images must be constantly recalculated.
The U.S. Pat. No. 5,625,765 (issued to Ellenby et al.) describes a system that makes it possible to improve the resolution of enlarged images by computer. The real images from one scene can be enlarged using the information contained in the computer which reproduces the real scene. Given that the resolution of the models contained in the computer is not limited, the system can present an enlarged image without restriction. The image produced by the computer and the real image are combined in order to form an enlarged image from the user""s point of view. This type of system is restricted to the improvement of the resolution of real images and does not allow the superimposing of a virtual environment which represents movable virtual objects and whose position is shared among several users, onto a real environment.
The U.S. Pat. No. 5,579,165 (issued to Michel et al.) describes an optical system that makes it possible to superimpose a virtual image onto a real image. The virtual image can be a symbolic image that comes from a map. This patent is limited to the optical device for the superimposing of images but does not describe its applications precisely. It is thus not possible from the elements of this patent to make an application involving the creation of a virtual interactive environment that is superimposed on the real environment.
The purpose of the invention presented here is to propose a mobile system for displaying virtual three-dimensional images inlaid on a background of a real environment, capable of following the movements of one or more users in real time and showing the results of its interactions in real time. The goal is to offer to each user the display of a virtual interactive environment superimposed on their real environment. The virtual environment can be shared by all users, each user perceiving it according to his point of view and certain elements of the virtual environment being able to be displaced by each user, the other users perceiving this movement in real time.
The device that is the object of this invention is thus a device for displaying realistic three-dimensional images calculated by computer, and inlaid by computer in the real environment. It contains at least one individual and portable device for capturing the real images perceived by the user (camera), a device for memory of the characteristics of the virtual objects to be displayed, a device for memory of the planned position of these objects in a real geographic environment, a device for following the user""s position, a device for following the user""s field of vision (head movements), a device for inputting the user""s commands, a device for calculation by computer including software for calculating images and which ensures the synthesis in real time of all of the devices cited above, and an individual and portable device for displaying the images calculated in this way, in a manner so that they are perceived three-dimensionally by the user, characterized in that it contains a combination of:
a mechanism for detecting and following in real time the position of each user in the geographic site for layout of the virtual objects relative to an arbitrary point of reference,
a mechanism for the detecting and following in real-time the position of the field of vision of each user (high, low, right, left) relative to a point of reference located on each user,
a video mechanism for capturing and following in real-time the images perceived by each user,
a database shared by all users containing the positions of each virtual object and storing their possible movements,
a mechanism for calculating virtual images in real-time taking into account the position and the field of vision of each user previously detected,
a mechanism for mixing the virtual image calculated in this way with the video image captured previously, in a manner so that, for each user, the virtual image is inlaid on the video image in a realistic and non-transparent manner; where the purpose is to send to each user equipped with a mechanism for individual and portable display, the image that is calculated in this way, combining the real outside landscape and the images of the virtual objects whose positions are shared by all of the users but displayed by each user at a different angle.
It is understood that using this device, the user will be able to simulate the implantation of an object such as a building, traffic circle, work of art, etc., into the real site planned for its implantation, with an extreme realism, thus making easier its decision making with regard to the different options of a project. This indeed involves a new manner of seeing and perceiving the space for users: they no longer go to the computer, but the computer comes to them in becoming integrated into their field of vision.
Also by this device, one can get around the absence of believability that occurs when numerous people are faced with the images presented on the video-type screen where the landscape, which has been numerically recalculated, appears in a style that is indisputably artificial (angular, jerky, few shades of colors, no natural movements, etc.). Here, the real image of the landscape is retained, since this involves a video retransmission, and a calculated virtual image is added, thus making easier its acceptance by the public. In fact, the familiarity that one experiences with the display of a video image renders more credible the integration of the plotted virtual image, which will then no longer only represent a small area of the global image.
According to a particular arrangement, the mechanism for the detection in real-time of the position of the user in the geographic site of the implantation of the virtual objects has the form either of a GPS system (global positioning system) by satellite link, containing a fixed station and mobile stations (backpacks weighing less than 4 kg) , or tracking video cameras, whose position is known precisely.
This device contributes to implementing the invention with the help of simple mechanisms that are already known.
The description that follows, made with regard to the attached drawings for the purpose of explanation and in no way restrictive, makes it possible to better understand the advantages, goals, and characteristics of the invention.